Clamshell bucket



Sept. 1924. Y

W. M. VENABLE CLAMSHELL BUCKET Filed Dec. 4, W23 3 Sheets-Sheet l WITNESS W. M. VENABLE Si. 9 392%, r

cLwsnELL Bucxm Filed Dec. 4, 1923 I5 Sheets-Sheet Z INVENi'OR.

. 1,508,037 w.- M. VENABLE 'CLAEASHELL BUCKET Sept. 9 1924.

Filed Dec. 4, 1923 v s Shee'gs-S'neot. s

i atented fiept. 9, 1324.

ITEDJ meat-3i earns-r esters;

WILLIAM ivr. vnnABLn,or rirrseuaen, PENNSYLVANIA, assreno'n TO' anew-Knox COMPANY, A oonronarron' or New JERSEY.

GLAMSI'IELL BUCK-Eff.

Application filed December 4, 1928. 1' SerialNo. 678 ,3741

This invention relates to excavating. buckets of the so: called clam shell" type-and is more especially useful in connection with two" line buckets; that is buckets which are provided with separate holding and operat ing lines or cables;

Thep'rincipal object of the invention resides-in the provision ofan improved mount ing for the sheaves which will ensure at all times substantially straight leads for the cable between the sheaves in the head and the sheaves associated with the scoops. Inconnection with this prov-ision it is a further objectuof this inventionto-make the scoop sheaves movable and'to properly guide them in their movements during operation of the bucket.

A further object of theilinvention relates to .the'provision of an improved head constructionlfor; the bucket as well as improved guide means for the closing line as it passes through the headt A=furtherobyect of the invention relates to a sheaveand line holdingarrangement which willpermit the bucket'to be usedeith'er with great or moderate closing power orwith less liftingpower. I

Still another object has to do with theprovision of 'an improved bearing arrangement-"for the sheaves associated-with the scoops. 7

Other objects will appear to those skilled in the art as the description proceeds The advantages also will more clearly appear.

The accompanying drawings represent my improvements in their preferred form,;l31gure '1 being a side elevation-of the bucket 1n closedposition; Figure 2 aside elevation of the bucket in openposition Figure-3 anend elevation" of the bucket in closed position from theright of- Figure 1; Figure 4 a partial' end elevation'similar to Figure 3 but illustrating a type of reeving which requires less power to lift? the bucket although theclosing power is not quite so'great'; Figure 5 anenlarged detail partially 1I1 S6Qb1011 1llustrating. the: improved bearings; and Fig of theseoo'ps. Gorner bars Sand 9 extend-- from the; upper outer corners ofthe scoops 1 and-2 to the head casting 10, theilatter hav ing: an extension 11 by means-of which it canbe welded, riveted-er other-wise secured to-the bars 9 in order to vform; a rigid /-\-frame structure with the bars.

The closing lever arm construction indi cated as a whole by the reference character A (see 'particularly Figure 3) is shown, in this instance, as comprising n the twoside plates :12 which are of obtuse triangular form.= Each plate is providedwith a hub portion 13 adaptedto embrace the hinge pin 3 and the two plates are spaced apart and secured together by means of the plates- 14 and 15. The lower ends of the members 12 may project downwardly into the upper edge of the-scoop 2. vI wish it to be understood, however; that the-lllVelltlOll 1s notllmitedto this particular lever; arm construct-ion-sinceany one oI-a number ofarrangements might: k

be used equally. well,

The bucket .is opened by dropping the hinge 3, the scoops swinging outwardly and downwardly upon the pins 16 and 17 join-,

inggthemtto the corner bars;v This is clearly shown in F igure 2; In=order .to close the bucket the power of the closing-line or cable 18 is applied. to the upper end ofthe lever- A sheave block 19 is arm construction. pivoted upon the pin 19 between the upper ends of the members 12. A pair of sheaves 20; andQO are mounted upon the sheave pin 21 in the upper portion of the block rand-lit.

will beinotedathat the pin 21. is set at an angle oris canted with respect-to thepin 19 upon which the block/rotates.

This angular placement has been proposed before in-an'attemptto get as nearly straight leads as-possible for the 'cable- (see applicants formed Patent-No. 1,34t( 3,999)v but the angula-rity (110118dSmllOC-SllffiGlBlIt for the reason that during operation of the bucket the relation of this pin to the pin inthehead isconstantly 'changnig,v By means ofthe pm 19% however, I am enabled to-provldesuo stantially straight leads for the cable be tween the sheaves and 20 and the head sheaves 22, 22 and 22 in all positions of the scoops. As the bucket opens, for instance the block 19 is free to rotate slightly on its pin 19 in a clockwise direction. This motion serves to maintain a constant relation between the sheaves in the head and the sheaves in the lever arm which relation would appreciably change in the absence of the pin 19*.

The reeving shown in Figures 1, 2 and S is as follows: The cable 18 comes down through the head and passes over one side of the sheave 22 and then makes a slight bend toward the left as it goes down and passes under the sheave 20. From the sheave 20 it passes upwardly and over the sheave 22 and then downwardly and under the sheave 20 and then upwardly and over the sheave 22", after which it can be extended downwardly to be secured to the lugs 24 which project upwardly from the hinge pin 3 through slots in the plate 14:. There are three of these lugs 2a illustrated through the upper ends of which is passed a pin 25.

This reeving will give a very strong closing power suitable for hard digging but for easier work it may be unnecessary. I have provided the head with a hole 26 through which a pin may be inserted to which the end of the cable 18 may be fastened after it passes upwardly from the sheave 20 and without passing over the sheave 22". This is shown in Figure t. If even less closing power is necessary the line need not be reeved under sheave 20, but may be made fast to the pin 25 at a point to the left of that illustrated in Figure 3, the pin 25 be ing made sufficiently long and the lugs 2 1 being so disposed as to permit this and still maintain a straight lead for the cable to sheave 22.

As long as the lines which operate the bucket are under load, the block 19 is swung to the proper position upon the pin 19 to give the desired straight leads but when the lines are slack they can not function to maintain this relation, so I have provided the fol lowing guide mechanism. v

A pair of guide arms 27 (one may suffice in small buckets) are pivoted to lugs 28 on the hinge castings a and at the opposite ends to the aligned lugs 29 on the block 19.

As the bucket opens these guide arms 27 rotate the block 19 in a clockwise direction with respect to the lever and they act to keep the block 19 lined up in approximately the most advantageous position for securing straight leads between the sheaves in the block and the sheaves in the head. The connection at one end of the guide arms is of a lost motion character. In the present instance the upper connection is so shown and by examining Figures 1 and 2 particularly it will be seen that there is a slot 30 in the member 27 which engages a pin 31 entering into the lug 29. In case there is any distortion of the parts of the bucket while undergoing strain in use a little play is allowed for the block so that it is not held rigidly in exactly the proper position although it is kept from becoming displaced to any great extent from the best position especially when the bucket is set down and the lines are relaxed. The stops 6 and 7 prevent the guide bars from be coming fouled with the hinge pin 3, as well as limit the bucket opening.

The underside of the block 19 is pro vided with a base or bottom portion 32 which is intended to rest upon the material when the bucket is set down and also to act as a guard for preventing the block from descending into the material with the fouling of the sheaves thereby made probable.

The head 10 is a one piece steel casting with guide rollers 33 mounted therein at each side of the line instead of guide rollers fore and aft as heretofore commonly in use.

The lifting cable 34, when the bucket is reeved as shown in Figures 1, 2 and 3, is simply secured around the pin 35 transverse 1y disposed in the upper portion of the head casting 10. In cases where the reeving of Figure L is used the third sheave 22" in the head is made available for use with the lifting or holding line 34: which is run down from the boom and under this sheave and then back to the boom in a manner very well understood in this art, so that the bucket is lifted up and down in the bight of the line 34. This gives greater lifting power but cuts down upon the closing power. It is extremely advantageous to construct the bucket so that it is possible to use it in either one of these ways, as with the additional sheave in the lifting line it may become possible to operate on loads of twice the size that could be lifted without it on a given engine although at reduced speed.

Turning to Figure 5 it will be seen that the block structure 19 is provided with pair of oppositely disposed bearings 36 and that the sheave 20' is keyed directly to the pin 21 by means of the key 37. The sheave 20 is free to rotate independently of the pin 21 and I have shown a bushing or bearing 38 between the pin and the sheave which is keyed to the latter. The two sheaves are rotating of course in the same direction. By making the sheave 20 rotate with the pin it is possible to reduce the amount of wear between the sheave 20 and the pin 21. The construction also makes possible the enlarged bearings 36 at either end of the pin outside Of the sheaves. The

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mos-ma? bushings r 39 are provided within the bearing suitable oil or grease holes: At the sides ot' the sheaves-'1'. pro-vide bands of met-al ll made in: three sections bolted togetherunder wlnch I place; wick -packings 42 so'that': When-the bucket isused under water, sand and grit can-notreach the bearings. The operation of: the bucket is as follows From the closed position of Figure 1 which, let us assume, represents an: empty bucket,

the open: position shown-in Figure 2 is first assumedby slackening awayon the closing cabler18 As tlie hinge-drops fromtheapo sition shown in Figure l to that shown -in' Figure '2 the -:guicle.=-arn1s= 27 will rotate the block 19 in a clockwise direction so asito niaiiitain atall times-straight" leads for the cable. The bucket is set down upon the material to be excavated in the open position shown in Figure 2. The closing cable 18 which is now pulled up acts to raise the hinge and to close the bucket. The bucket is now swung by the derrick from the holding line 34 and moved to the desired position for discharge. In order to discharge the contents the cable 18 is slackened so that the bucket will again assume the position shown in Figure 2 ready to be once more applied to the material to be excavated.

I claim:

1. A lever arm bucket comprising in combination a pair of coaxially mounted head sheaves, a sheave block pivoted on the lever arm, a sheave mounted in said block upon an axis which is canted with respect to the pivot of the sheave block and an operating cable reeved between said sheaves, said cable, said pivot for the sheave block and said axis for the sheave in said block all cooperating to maintain substantially straight leads for the cable regardless of the constantly varying relation between the head sheave and the block sheave during actuation of the bucket.

2. A lever arm bucket comprising in combination with an operating cable, a pair of head sheaves mounted side by side on the same pin, a sheave block pivoted on the lever arm upon an axis which is parallel to the axis of the head sheaves, a sheave in said block on an axis so canted with respect to the axis of the bucket that a line reeved under one head sheeve, under the, lever sheave, over the second head sheave and thence to the lever arm may pull the pivoted lever arm block into alignment that will insure substantially straight leads for the lines between the head sheaves and the lever sheaves in all positions of the lever arm.

3.. In] a: lever arm.- bucketx which isvopereated iby -acable reeved ibetweenasheaves 1n? the headfand asheave inr'the armp the come bination or; means: *for moving the-'- arrmsheave during: operation 0t thebucket 'so' "as.

to: maintain substantially' stnaight leads for the cable at all'pos'itions ofitheshellh 4. Ailever arm bucket comprising in combination'with the operatingvcable, a pair :of

pivoted-scoops;'a pair' 0t lieadi sheaves, a movable I l8V8I- f'rll IIP sheave -b-lock, a sheave; angul'a' 'ly mounted in said block, rand means r formoving the block-"during operation; of

the bucket whereby "substantially straight leads are maintained ati allrtimes.

5. A bucket comprising in combination-.3:

withrthe operating cable, a pair of pivoted scoops; ahtclosingrlever-z arm, a pair of head" sheaves,- a sheave bloele'movably nrounted in 'the lever-arm; a sheaa e set in said -block1 ata11*-a11'gle-to*the head sheaves so as to; give substantially straight 'leads for the" cable," and means for moving the block during operation of the bucketwhereby substantially straight leads are maintained at all times.

6. A bucket comprising in combination with the operating cable, a pair of pivoted scoops, a closing lever arm, a'pair of'head sheaves, a sheave block mounted in the lever arm upon an axis which is parallel to the axis of the head sheaves, a sheave mounted in said block at an angle to the head sheaves, and means for rotating the block during operation of the bucket.

7. A bucket comprising in combination with the operating cable, a pair of pivoted 1 scoops, a closing lever arm, a pair of head sheaves, a sheave block mounted in the lever arm upon an axis which is parallel tothe axis of the head sheaves, a sheave mounted in said block at an angle to the head sheaves,

and a guide mechanism for the sheave block connected between a scoop and the block,

adapted to rotate the block during operation of the bucket so as to maintain substantially straight leads for the cable at all positions a of the scoops.

8. A bucket comprising in combination with the operating cable, a pair of pivoted scoops, a closing lever arm, a pair of head sheaves, a sheave block mounted in thelever arm upon an axis which is parallel to the axis of the head sheaves, a sheave mounted in said block at an angle to the head sheaves, and a guide mechanism for the sheave block connected between a scoop and the block adapted to rotate the block during operation of the bucket so as to maintain substantially straight leads for the cable at all positions of the scoops, said guide mechanism having a lost motion connection to one of sheaves, andmeans for securing the closing line either to the scoops or to the head, so that one of the head sheaves is available upon occasion, either as a closing sheave for increasing the closing power of the bucket or as a lifting sheave for decreasing the lifting power required to hoist it.

10. In a lever arm bucket the combination of an integral block pivoted to the lever arm, an integral head, a pair of corner bars rigidly secured to said head, a pair of corner bars pivoted to said head, sheaves in the head mounted on the same pivot, and sheaves in the lever arm block mounted upon an axis Which is set at an angle to the said pivot.

11. In a lever arm bucket, an integral bucket head construction comprising in com bination with the head sheave and the operating cable, a pair of rollers mounted in the head at each side of the cable for guiding the cable to said head sheave.

12. Ina lever arm bucket, block construc tion for a pair of sheaves Which rotate at different speeds in the same direction con1- prising in combination, a sheave pin, means for keying one sheave to the pin, and ex.- tended bearing means at each end of the pin beyond the sheaves.

13. In a lever arm bucket, a bucket block construction comprising in combination, a pin, bearing means for the pin, a pair of sheaves on the pin, and means for securing one sheave to the pin so as to rotate the latter, the other sheave being free on the pin.

1a. In a lever arm bucket, the combination of a sheave block pivotally connected to the lever arm, and a shoe carried by the block which acts as a guard When the bucket is set down open upon the material to be excavated.

In testimony whereof, I have hereunto signed my name.

WILLIAM M. VENABLE. 

